The protection of fragile erythrocytes against mechanical injury

Abstract

In the preceding paper the fact has been stated that erythrocytes handled in salt solution undergo an injury which does not take place when they are in plasma. This has suggested tests of various substances for a protective action. We have found that the addition to Ringer's solution of gelatin in very small quantity—1/6 of 1 per cent.—protects the red cells completely, and that their prolonged sojourn in it is no more harmful than in plain Ringer's. Dog corpuscles which break down almost at once when shaken in Ringer's solution, resist prolonged shaking when in the gelatin-Ringer's. Corpuscles of the dog, rabbit and sheep, washed in this fluid and placed in ordinary Ringer's, remain intact much longer than when washed in the latter. Dog erythrocytes may keep several days, whereas when washed in plain Ringer's solution they break down within a few hours. Only in the case of human red cells does the protection afforded by gelatin seem unnecessary during washing. These cells last quite as well when handled in plain Ringer's.

That the erythrocytes of certain species differ markedly as regards the time they remain intact when washed and placed in isotonic salt solution, is well known. The experiments with the gelatin-Ringer's solution show that this is due for the most part'to differences in the fragility of the erythrocytes. Corpuscles of the several species in question, protected with gelatin during washing and placed in plain Ringer's, differ relatively little in their period of survival.